The present invention relates to a digital volume control circuit for use in a digital audio system, and more particularly, to a circuit for preventing deterioration of the sound quality generated during operation in the digital volume control circuit.
A known digital volume level control is accomplished by multiplying an input digital audio data by a given number of multiplying coefficient, for which the digital audio system generally deals with 16-bit digital audio data of both right and left channels as shown in FIG. 1A, wherein a so-called "bit down" phenomenon, as seen by FIG. 1B, occurs when the level of more than 6-decibel(dB) is attenuated. As such, since the 16-bit audio data are shifted upon the attenuation, the audio data bits existing in the LSB (Least Significant Bit) of the digital audio data are removed, which is the occurrence of the bit down, thus resulting in deterioration of the sound quality due to reduction of the dynamic range of signal.